The "eAuthentication" system which maintains user account information for the USDA usually classifies an account as inactive if the e-permits system has not been accessed for 400 days. Inactive accounts can usually be reactivated by contacting the eAuthentication Help Desk.
Unfortunately, many inactive accounts were accidentally purged from the system in the summer of 2012, so they cannot be reactivated. If you attempt to log into the e-permits system and your account no longer exists, you should complete the registration process again. If you enter your former user name and choose a new password, you should be able to access your account information including archived permit applications.